The urgent need to improve the viability, ultrastructural morphology and functionality of engineered cardiac tissue has been addressed by growing cell constructs in advanced bioreactors providing high mass transfer or exposing the tissues to electrical (Radisic, M., et al. Pro. Na. Acad. Sci. USA 101, 18129-18134 (2004)) and mechanical cues (Zimmermann, W. H., et al. Circ. Res. 90, 223-230 (2002); Dvir, et al. Tissue Eng. 13, 2185-2193 (2007)). Scaffold structural and mechanical properties can be improved by microfabrication processes that provide controllable stiffness and anisotropy (Engelmayr, G. C., et al. Nature Mat. 7, 1003-1010 (2008)).
Engineered cardiac patches to replace scar tissue after myocardial infarction can be produced by seeding cardiac cells within porous three dimensional (“3D”) biomaterials, which provide mechanical support while cells organize into a functioning tissue. However, success can be jeopardized by a lack of electrical conductivity within the construct. Electrical signal propagation between cardiomyocytes in separate pores is impeded by biomaterial resistance, limiting the patch's potential to contract strongly as a unit.
It is therefore an object of the present invention to provide tissue engineering scaffolds which can provide electrical stimulation to cardiomyocytes seeded into or onto the scaffolds.